The island has a deserved reputation as an excellent place to shop, rivalling Saint Thomas in the US Virgin Islands for price, but with somewhat fewer stores. Some shoppers report better prices for some items than the USVI. Both "sides" offer a wide range of quality. Shopping is duty free on both sides of the island, with no tax or duty paid directly by buyers. Merchants on the "Dutch" side" do pay a five percent "turnover tax" on all items they sell...recently February 11, 2011 increased from 3% by the new government. A few sellers may try to add it as a separate cost item on sales slips, despite instructions from the tax authority not to do so.
French side. Items are often priced in euros on the French side, so some items are or appear to be more expensive after currency conversion than on the Dutch side or elsewhere in the Caribbean. Many stores on the French side close between 12 and 3PM. That side has a smaller number of retailers, and their goods e.g., clothing, perfumes, wine tend to be premium, European brand-name or designer items at fairly competitive prices.
However, unique items e.g., souvenirs, spices particularly at the water-front open-air market large and growing in Marigot are reasonable, and the banter among vendors is worth the visit...especially mornings on Wednesday and Saturday.
French wine and delicacy lovers may find premium offerings on this "side" that are available perhaps nowhere else in the Caribbean.
If you are shopping on Sunday, forget the French side...the only places open are most restaurants and some food stores.
Dutch side. Front Street in Philipsburg is the centre of shopping on the Dutch side. Numerous stores offer jewellery, liquor, cosmetics, cameras, electronics and tobacco, with souvenirs everywhere; you'll find a small open-air bazaar behind the courthouse.
Those looking for well-priced beachwear and souvenirs might try the few places on Back Street...one block farther from the beach than Front Street and parallel to it.
Grand Marché and Sangs supermarkets the latter beyond the east end of Front Street in Philipsburg both offer a wide range of items, e.g., mild Dutch Gouda are popular buys.
Shops are generally open from 8 or 9AM until noon, and then again from 2 until 6PM If one or more cruise ships are visiting, many stores remain open during the "lunch" period and on Sundays.
Amsterdam Cheese & Liquor Storenext to Chesterfields Restaurant in Philipsburg 5 minutes away from the cruise terminal offers a wide range of Dutch cheese and with their premium cheese the Old Amsterdam, they also have Dutch treats like chocolate, stroopwafels,etc. They also have a large selection of wines and liquors. The store is open Monday to Saturday from 8:30 AM to 5:30 PM
Warranties: Any electronics including cameras, lenses purchased here will have an international warranty...or grey-market or none. You should clearly understand what any warranty covers and what's necessary to obtain service at home.
Store recommendations by cruise ship port shopping "advisers" are usually reliable, but the stores pay very large fees for those "endorsements"...virtually all for stores on the Dutch side. Recommended by advisers or not, large or small, most stores e.g., Kay's Jewellery are reliable, and will rectify any problem truly their responsibility. You're wise to thoroughly examine an item before purchase & obtain a warranty, or formal appraisal for pricey gems/jewellery.
AVOID World of Electronics, they have history of falsely describing items such as an Apple iPhone 4S which Apple have confirmed is not an Apple iPhone 4S.
Most merchants touted by those "advisers" are near or east of the courthouse on Front Street. Those stores and others offer excellent selections. The centre and easterly parts were recently renovated for pleasant walking despite heavy vehicle traffic and sometimes crowded pavements. Many liquor stores there box bottles and may deliver to your hotel or ship if purchased early enough. West of the courthouse, and on "Old Street", you'll find smaller stores, e.g., for aggressively discounted liquor...often cash-only, boxes only for multi-bottle purchases, usually no delivery so you'll need a sturdy bag and padding to safely carry bottles. See Saint_Thomas#Returning_home for tips on going home with purchases.
Whenever considering a significant purchase, negotiate amiably; you may well save a bit.
Anyone on the streets touting "freebies" or "cash" will likely lead you incrementally and smoothly to a distant, on-site sales pitch for resort condos or time-shares. Once there, you'll encounter high-pressure tactics over an extended time, with "freebies" governed by willingness to buy. If you have only limited time for your visit, it may be totally consumed at the sales pitch.
St Martin is a duty-free port, so merchants pay no up-front duty or tax as they price merchandise. They must, however, pay the above 5% "turnover tax" TOT, and those funds come from somewhere...you.
It offers no special customs duty advantages over other Caribbean islands, and for U.S. citizens a slight disadvantage compared to the U.S. Virgin Islands.
Nonetheless, you may find well-priced items here that you won't find elsewhere, and prices on commodity items e.g., some premium liquors, wines may be better than the USVI. Take care when calculating cost per litre for purchases, and when declaring litres for Customs, because bottle sizes vary. Don't allow yourself to be dissuaded from a purchase here just for fear of customs duties, which may be modest. See Saint_Thomas#Customs_and_Duty for U.S. Customs details.